From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964843AbWGMIyr (ORCPT ); Thu, 13 Jul 2006 04:54:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964816AbWGMIyr (ORCPT ); Thu, 13 Jul 2006 04:54:47 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:53473 "EHLO mx3.mail.elte.hu") by vger.kernel.org with ESMTP id S964843AbWGMIyq (ORCPT ); Thu, 13 Jul 2006 04:54:46 -0400 Date: Thu, 13 Jul 2006 10:49:12 +0200 From: Ingo Molnar To: Andrew Morton Cc: sekharan@us.ibm.com, torvalds@osdl.org, linux-kernel@vger.kernel.org, nagar@watson.ibm.com, balbir@in.ibm.com, arjan@infradead.org Subject: Re: Random panics seen in 2.6.18-rc1 Message-ID: <20060713084912.GA7240@elte.hu> References: <1152763195.11343.16.camel@linuxchandra> <20060713071221.GA31349@elte.hu> <20060713002803.cd206d91.akpm@osdl.org> <20060713072635.GA907@elte.hu> <20060713004445.cf7d1d96.akpm@osdl.org> <20060713074609.GA3620@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060713074609.GA3620@elte.hu> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: 0.1 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.1 required=5.9 tests=AWL,BAYES_50 autolearn=no SpamAssassin version=3.0.3 0.0 BAYES_50 BODY: Bayesian spam probability is 40 to 60% [score: 0.5000] 0.1 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Ingo Molnar wrote: > but ... i think gcc ought to be able to figure out that the parameter > is totally unused on !LOCKDEP - all functions involved are static, and > we are using -funit-at-a-time already. That should make the parameter > passing totally zero-cost. hm, gcc (as of 4.1.1) doesnt seem to be able to figure that out, probably due to the 'nesting + 1' changing the variable. Anyway, Arjan's nesting-type idea should solve the problem - in that case 'nesting + 1' becomes an identity mapping of a zero-sized variable, which will generate zero code. Ingo